Flacco tossed for 309 yards 25-of-36 efficiency with no interceptions as the Ravens (10-5) snapped a three-game losing streak and claimed their second divisional title in two years.
New York (8-7), meanwhile, fell for the second straight week and dropped a game behind Washington in the NFC East as Eli Manning was held to 150 passing yards and a touchdown.
The Giants' offense could muster only 186 yards of total offense in the setback.
UPI Sports Results for September 20, 2014
UPI Sports Results for September 19, 2014